Things To Consider When Measuring Pressure; General; Pressure Type - BEAMEX MC5-IS User Manual

Things to Consider when Measuring Pressure

General

Pressure Type

MC5-IS can measure pressure with its internal pressure modules,
or with external pressure modules. If a barometric module is
present, the measurement results of other modules can be shown
either as absolute pressure or as gauge pressure.
Every pressure measurement is in fact a pressure difference mea-
surement: a given pressure value is compared against a refer-
ence pressure. In certain cases the reference pressure has a
special meaning (like the atmospheric pressure) and the pres-
sure measurements with reference to against these points are
given a special name:
•
Absolute pressure measurement uses vacuum as the ref-
erence pressure.
•
Barometric pressure (or atmospheric pressure) is the ab-
solute pressure of the surrounding atmosphere. It is spe-
cially titled because of its importance.
•
Gauge pressure measurement uses the atmospheric pres-
sure as the reference. Gauge pressure may be zero, negative
or positive. Most of MC5-IS' pressure modules actually mea-
sure gauge pressure although they may be used for measur-
ing other pressure types too.
•
Differential pressure measurement requires a special dif-
ferential pressure module that has an input available for both
the reference pressure and the given pressure.
To be able to measure absolute pressure with MC5-IS' gauge
pressure modules, you need a barometric pressure module. Cer-
tain high pressure modules may approximate absolute pressure
measurement by adding an entered barometric pressure to the
measured gauge pressure.
MC5-IS may use two standard pressure modules to measure dif-
ferential pressure: One module measures the reference pres-
sure and another the given pressure. The pressure difference is
calculated by subtracting the reference pressure from the given
pressure. More of this in Part B, chapter Special Measurements.
Always ensure that the pressure type setting of your pressure
measurement is what you intended it to be. The pressure type
setting is crucial for getting meaningful pressure measurement
results.
Additional Information
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